The objective of this Phase I SBIR application is to develop novel red fluorophores with large Stokes' shift and high quantum yield. Chromagen has already developed two novel fluorophores with trade names StarBright Green and StarBright Orange. The long-term objective of the proposal (Phase II) is to utilize the novel red fluorophores in gene expression assays to detect multiple messenger RNA (mRNA) targets in a high throughput screening (HTS) format for pharmaceutical drug discovery. Such an oligonucleotide based, simultaneous multi-target detection system will greatly facilitate monitoring expression of genes involved in cancer and other diseases and drug discovery that requires a high throughput screening format. The technological innovation of the proposed research lies in the novel design and successful synthesis of a series of polycyclic aromatic compounds which will result in red fluorescent dyes that possess photo-stability, high quantum yields, and large Stokes' shifts. Developing inexpensive, fast, facile and ultrasensitive multi-target gene expression assays will contribute to the technological advancement of molecular research and clinical diagnostics. This will be a proposal for a Phase II grant application. Chromagen has already demonstrated its ability to develop assays to detect two targets in the same micro-well in a high throughput screening format. Developing a triple target gene expression assay will not only enhance the gene discovery process, but will also expedite the identification of lead drug candidates in the pharmaceutical industry. PROPOSED COMMERCIAL APPLICATION: An ultra-sensitive, photostable red fluorophore with large Stokes-Shift will have tremendous commercial applications in Flow-Cytometry, In-Situ Hybridization, Nucleic Acid-based Hybridization.